著者
今野 浩
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.1, no.1, pp.36-50, 1991-03-15 (Released:2017-04-08)

Recently, a remarkable progress has been made in the field of the global minimization of nonconvex functions over a polytope. The purpose of this article is to survey one of the most successful approaches in this field, namely parametric programming approaches to quasilinear nonconvex minimization problems. The problems to be discussed are: linear multiplicative programming problems, i. e., the minimization of the product of two affine functions; minimization of the sum of two linear fractional functions; minimization of concave quadratic functions and bilinear programming problems. It will be shown that a global minimum of a fairly large scale problems can be obtained efficiently by applying parametric simplex algorithms. Further, it will be shown that a convex multiplicative programming problems, i. e., the minimization of the product of two convex functions, can be solved by parametrizatioh and branch and bound techniques.
著者
神保 秀一
出版者
一般社団法人日本応用数理学会
雑誌
応用数理 (ISSN:09172270)
巻号頁・発行日
vol.11, no.2, pp.152-162, 2001-06-15

本稿ではギンツブルグ・ランダウ方程式(以下GL方程式と呼ぶ)およびボルテクス(vortex)についての偏微分方程式の立場からの近年の研究について述べる.GL方程式は物理において超伝導や超流動の現象で電流や流体の状態を記述する方程式として現れる.ボルテクスはこれらの流れの停留する点であり,また,その近傍にエネルギーが偏在する点でもあり,状態を特徴付ける重要な性質である.一方,ボルテクスは数学的には解の関数(Φ=Φ(x))のゼロ点に対応するが,解としての幾何的な性質を特徴付ける興味ある対象である.また,解の安定性や大域的な性質を調べるうえでも手がかりとなるので重要である.その解析のために非線型解析の方法が華々しく応用される.特にGL方程式のなかの小さいパラメータの極限(特異摂動)において,ボルテクスの挙動を求める研究が注目を集めている.このような事情でGL方程式は近年(90年以降)ホットな研究テーマであり続けている.
著者
村木 尚文
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:09172270)
巻号頁・発行日
vol.13, no.2, pp.137-149, 2003
参考文献数
37

One of the main features of quantum probability(=noncommutative probability) is the diversity of notions of 'independence' for noncommutative random variables. Besides the three fundamental examples of universal independence (tensor, free and Boolean independence), there is another example called 'monotone independence' which was introduced and studied by the author. We give a brief review on 'monotone probability' which can be developed based on the notion of monotone independence. Especially we present the monotonic analogue of central limit theorem, law of small numbers, convolution, infinite divisibility and Levy-Hincin formula. Furthermore, we give a classification theorem for universal notions of independence.
著者
畔上 秀幸
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.11, no.3, pp.245-248, 2001-09-14 (Released:2017-04-08)
参考文献数
10
著者
櫻井 鉄也
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.13, no.4, pp.308-317, 2003-12-25 (Released:2017-04-08)
参考文献数
14

In this paper, we consider a method for finding certain eigenvalues of generalized eigenvalue problems in a given domain of the complex plane. We also discuss the relation between the presented method and the Lanczos method briefly. The presented method provides a good performance in parallel computations. A numerical example that was obtained on a PC cluster is included.
著者
杉原 厚吉
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.1, no.4, pp.280-299, 1991-12-16 (Released:2017-04-08)
被引用文献数
1

New approaches are presented to the problem of topological inconsistency caused by geometric algorithms implemented in finite-precision arithmetic. In geometric computation numerical errors often create inconsistency in topological structures and thus cause theoretically correct algorithms to fail. To overcome this problem two approaches are considered for the case of constructing the Voronoi diagram as an example. In the first approach, higher-precision arithmetic is used to construct a closed world in which topological structures are judged always precisely, and the symbolic perturbation technique is employed to avoid complicated branches of processing for degenerate cases. In the second approach, the highest priority is placed on the maintenance of topological consistency and numerical results are used as lower-priority information; the resultant algorithm is robust in the sense that inconsistency never arises and is correct in the sense that the output converges to the true solution as the precision becomes higher.
著者
蔵本 由紀
出版者
一般社団法人 日本応用数理学会
雑誌
応用数理 (ISSN:24321982)
巻号頁・発行日
vol.17, no.2, pp.175-177, 2007-06-26 (Released:2017-04-08)
参考文献数
4
被引用文献数
1